Invented by the French mathematician Édouard Lucas in 1883, this is a mathematical game/puzzle about moving a set of disks between a set of pegs, limited by the following rules :

* Only one disk may be moved at a time.
* Each move consists of taking the upper disk from one of the pegs and sliding it onto another peg, on top of the other disks that may already be present on that peg.
* No disk may be placed on top of a smaller disk.